Chronic post-surgical pain (CPSP) is a major cause of new chronic pain, occurring between 10 - 40% after common surgical procedures. Thoracic surgery procedures have among the highest rates of chronic post- surgical pain (CPSP), with roughly 30 - 47% of patients developing new chronic pain within 6 months of surgery. While the high incidence of CPSP following thoracic surgery is well-described, the patient- and care- factors associated with the development of CPSP are still not clear. Some factors such as anxiety have been described; however, most cohorts lack the sample size to assess potentially important factors, including neuroimaging, quantitative sensory testing, and blood samples for genomics, metabolomics and proteomics. We believe that thoracic surgery is an ideal second surgical population to add to the Acute to Chronic Pain Signatures (A2CPS) program, complementing the first MCC population of knee arthroplasty, which has much lower rates of new CPSP but is a better cohort to identify risk factors for failure to resolve chronic pain. Our inter-disciplinary team from the proposed University of Michigan A2CP Multisite Clinical Center (MCC) has unparalleled expertise to examine the phenotypic and genotypic risk factors for the development of CPSP among patients undergoing thoracic surgery. Our co-PIs include an anesthesiologist, two surgeons, and a rheumatologist that have successfully collaborated in ongoing work, and partner within a statewide network of hospitals performing thoracotomy procedures, the Michigan Society of Thoracic and Cardiovascular Surgeons (MSTCVS) Quality Collaborative. Collaborative quality improvement programs including MSTCVS are funded by Blue Cross Blue Shield of Michigan to conduct participatory, provider-driven quality improvement initiatives, and our team has heavily leveraged these to study postoperative pain- and opioid-related outcomes and generate best practices. The implementation and dissemination of these best practices has dramatically reduced perioperative prescribing of opioids in the state of Michigan, and this strong partnership will enable us to recruit thoracotomy patients from a population-based sample across diverse healthcare systems. We will recruit 1800 patients from seven hospitals in Michigan undergoing surgery via a thoracic approach (lung resection, esophageal resection/reconstruction, and other general thoracic surgery). We will capture patient-reported health status alongside QST and functional neuroimaging at baseline and 6 months using a novel smart phone- and web-enabled application. At baseline and 6 months, biological samples will also be collected. From the 1800 participants recruited, we will identify 200 cases and 200 controls of CPSP at 6 months after surgery for repeated neuroimaging, quantitative sensory testing and blood sample collection. The successful completion of the proposed study would provide an unparalleled resource for the understanding the factors associated with CPSP and will allow for more efficient and personalized trials to prevent the development of chronic pain after thoracotomy and other thoracic surgeries.